Dampening roller



Jan. 3, 1961 M. c. SWOPE 2,966,723

DAMPENING ROLLER 7 File Fabric Buck Adhesive Plastic Sheet Adhesiveuummmmmwm [WIN]llllIllllllllliflllllllllllllllllllll DAMPENING ROLLERMorris C. Swope, Bryn Mawr, Pa., assignor to Perfex Corporation, BrynMawr, Pa., a corporation of Pennsylvania Filed Apr. 14, 1958 Ser. No.728,224 2 Claims. (Cl. 29-120) This invention relates to dampeningrollers of the type used in lithography for carrying moisture to thestone or lithographic plate.

In lithography, it is important to provide a suitable means of dampeningthe stone or plate in connection with the printing process. This hasbeen done in the past by rollers to which a layer of molleton or pilefabric has been suitably secured, as by adhesive, and sewing.

When adhesively-coated pile fabric has been utilized, it has beennecessary for the workmen to measure the circumference of each rollerand to cut from a supply roll the necessary length of the pile fabric inorder to provide the moisture-carrying covering. Besides the accuracyrequired in measurement in order that the ends of the covering materialshall meet along a line, there is always the possibility the fabric maybe cut too long. If cut too short, the covering may have to bediscarded.

It is an object of the present invention to provide coverings fordampening rollers pre-cut to size and which not only havepressure-sensitive adhesive for securement of the covering to the rollbut in addition provides adhesive coatings which are pressed together inthe final bonding operation tightly to secure the covering on the rollerand to provide a greater strength in the region of the seam. Inaddition, the present invention provides a moisture barrier between themoisture-carrying pile fabric and the roller itself with a meeting seamdisplaced from the meeting seam of the outer layer. The moisturebarrier-layer protects the roll from deterioration due to constant watercontact. With the barrier-layer the roll will neither rot nor becomefatigued.

For further objects and advantages of the invention and for a moredetailed description thereof, reference is to be had to the accompanyingdrawing in which:

Fig. l is a sectional view of a dampening roller embodying the presentinvention;

Fig. 2 is a side elevation of the prefabricated dampening cover for theroller of Fig. 1; and

Figs. 3 and 4 illustrate successive stages in the application of thedampening cover to theroller.

Referring first to Fig. 2, it will be noted that there is provided adampening cover for a roller which comprises a pile fabric, the pile 11aof which is secured to a fabric back 11b in manner well understood bythose skilled in the art. The exposed surface of the fabric back 11b iscoated with a pressure-sensitive adhesive 12. This adhesive layer in theregion beyond the end of a layer 13 has thereon a separable coveringmaterial as indicated at 12a. The covering material 12a, which may be ofkraft paper or the like, is of the type which can be readily strippedaway from the adhesive. This exposes the adhesive for purposes laterdescribed.

A moisture-barrier layer 13, preferably of a thin plastic material suchas polyvinyl chloride, polyethylene, cellophane, cellulose acetate, orthin rubber-like sheeting, either natural or synthetic, is adhesivelysecured as at 12 to the fabric back 11b. Upon the upper layer of themoisture-barrier 13, there is a layer 14 of adhesive of thepressure-sensitive type. To the layer 14 there is secured a coveringmaterial 14a, such as wax-coated or sillconecoated crepe or kraft paper,and of the type which can be,

stripped from the pressure-sensitive adhesive.

The dampening cover of Fig. 2 is characterized by the fact that aportion of the assembly including the moisture-barrier 13 extendsoutwardly from one end of the outermost moisture-carrying layer 11awhile that layer, 11a, extends outwardly of the moisture-barrier layer13 at the opposite end of the moisture-carrying.

assembly.

It will be understood that there will be provided a:

moisture-carrying cover of the correct length for each dampening rollerof different diameter. For the roller 15, made of rubber, the cover ofFig. 2 will be suitable.

In order to apply the covering of Fig. 2 to the roller 15 of Fig. 3, theprotective layer 14a is stripped from the.

pressure-sensitive adhesive 14. The roller 15, generally of rubber orrubber-like material, is then placed upon the adhesive coating so thatan edge of the covering extends along a line parallel to the axis of theroller 15. The roller can then be rotated by its stub shafts 16 in adirection indicated by the arrow and over the covering material. As theroller 15 is rotated, the pressure-sensitive adhesive 14 adheres to thesurface of the roller. As the roller 15 approaches the right-hand end ofthe covering, as viewed in Fig. 3, there will be attained the positionillustrated in Fig. 4 in which the respective ends of themoisture-barrier 13 will be brought into meeting relationship. At thistime, the protective materials or panels 12a and 13a will have beenstripped from the pressure-sensitive surfaces preparatory to the finaloperation.

After removing the covering materials 12a and 13a from the adhesive, thefinal securing operation is accomplished by moving downwardly theupwardly extending end of the pile 11a to bring into engagement the twoadhesively-coated surfaces. These surfaces form a double-strength bondbetween a narrow face portion of the moisture-barrier layer and theadhesively coated fabric backing. The end result is the covering of thedamping roller 10 with a moisture-carrying material which is lacking inany substantial separation at the seams. The covering assembly issecurely and tightly bonded to the roller 15. A portion of the coveringpartially overlaps another portion. These portions 17 and 18 aresecurely bonded together by the action of their adhesively-coatedsurfaces.

While cotton pile fabric 11a, 11b is preferred for the moisture-carryingcovering, it is to be understood that the water-carrying layer may be offoam rubber, molleton or polyurethane foam. These may be taken asexemplary of water-carrying materials which have moistureretainingproperties and yet are resistant to attack by inks, solvents and othermaterials used in the printing and lithographic arts. Any of thepressure-sensitive adhesives on the market may be utilized, though apressure-sensitive adhesive of the rubber latex type is preferred. Anexample of the latter type is one available on the market under thedesignation #387 from the Polymer Industries Company. The water-carryinglayer may also be a wetstrength paper, that is, a resin-treated paperwhich has high wet strength and which is wettable by the moisture it isto carry to the lithographic plates.

What is claimed is:

1. A dampening roller assembly characterized by a roller coveringcomprising a pile fabric of width corresponding with that of the rollerand of length substantially equal to the circumference of the roller, athin polyvinyl chloride sheet of width corresponding with that of theroller and of length equal to the circumfer- I atented Jan. 3,

chloride sheet opposite said pile fabric, the opposite face of saidsheet in the region extending beyond said other edge, and the back ofsaid pile fabric from its edge to the edge of said sheet, all beingcoated by a pressuresensitive adhesive coating, said polyvinyl chloridesheet being secured to the roller through the action of saidpressure-sensitive adhesive, the opposite end portions of said polyvinylchloride sheet meeting each other in close proximity, the extending endportion of said pile fabric being disposed with its pressure-sensitivecoating in faceto-face relationship with the pressure-sensitive coatingof the extending end portion of said polyvinyl chloride sheet toestablish a strong joint and in which the meeting edges of said fabricare displaced circumferentially of the roller from the meeting edges ofsaid polyvinyl chloride sheet.

2. A roller covering comprising an outer layer of pile fabric of. Widthcorresponding with the length of the roller to be covered and of alength equal to the circumference of the roller, an inner layercomprising a thin polyvinyl chloride sheet of Width corresponding withthe length of the roller and of length equal to the circumference of theroller, said polyvinyl chloride sheet being adhesively securedto theback, ofv said pile fabric. from a position spaced from one edge thereofso as to overlap the other edge thereof, a pressure-sensitive adhesivecoating the overlapping end portion of said polyvinyl chloride on oneside of the assembly and the overlapping end portion of said pile fabricon the other side of the assembly for the bonding together of said endportions, and panel means covering said pressure-sensitive coatings andseparable therefrom to expose said pressure-sensitive coatings forapplication to said roller, removal of said panels exposing theadhesively coated faces of said end portions whereby the adhesivecoatings thereon are brought into face-to-face relationship forestablishment of a strong joint in the region where opposite edges ofthe pile fabric are brought into face-to-face relationship on a roller.

References Citedcin the file of this patent UNITED STATES PATENTS

1. A DAMPENING ROLLER ASSEMBLY CHARACTERIZED BY A ROLLER COVERINGCOMPRISING A PILE FABRIC OF WIDTH CORRESPONDING WITH THAT OF THE ROLLERAND THE LENGTH SUBSTANTIALLY EQUAL TO THE CIRCUMFERENCE OF THE ROLLER, ATHIN POLYVINYL CHLORIDE SHEET OF WIDTH CORRESPONDING WITH THAT OF THEROLLER AND OF LENGTH EAUAL TO THE CIRCUMFERENCE OF THE ROLLER, SAIDPOLYVINYL CHLORIDE SHEET BEING ADHESIVELY SECURED TO THE BACK OF SAIDPILE FABRIC FROM A POSITION SPACED FROM ONE EDGE THEREOF SO AS TOOVERLAP THE OTHER EDGE THEREOF, AND THE FACE OF SAID POLYVINYL CHLORIDESHEET OPPOSITE SAID PILE FABRIC, THE OPPOSITE FACE OF SAID SHEET IN THEREGION EXTENDING BEYOND SAID OTHER EDGE, AND THE BACK OF SAID PILEFABRIC, THE OPPOSITE FACE THE EDGE OF SAID SHEET, ALL BEING COATED BY APRESSURESENSITIVE ADHESIVE COATING, SAID POLYVINYL CHLORIDE SHEET BEINGSECURED TO THE ROLLER THROUGH THE ACTION OF SAID PRESSURE-SENSITIVEADHESIVE, THE OPPOSITE END PORTIONS OF SAID POLYVINYL CHLORIDE SHEETMEETING EACH OTHER IN CLOSE PROXIMITY, THE EXTENDING END PORTION OF SAIDPILE FABRIC BEING DISPOSED WITH ITS PRESSURE-SENSITIVE COATING INFACETO-FACE RELATIONSHIP WITH THE PRESSURE-SENSITIVE COATING OF THEEXTENDING END PORTION OF SAID POLYVINYL CHLORIDE SHEET TO ESTABLISH ASTRONG JOINT AND IN WHICH THE MEETING EDGES OF SAID FABRIC ARE DISPLACEDCIRCUMFERENTIALLY OF THE ROLLER FROM THE MEETING EDGES OF SAID POLYVINYLCHLORIDE SHEET.